The practice of immigration law encompasses a broad range of legal environments, from business immigration law in which lawyers represent corporations seeking to employ foreign born workers to deportation defense which includes representing individuals detained by the federal government seeking release from detention and relief from removal. Immigration lawyers practice in large and small firms, non-profit agencies and government. Immigration law can generally be divided into two large spheres administrative or affirmative practice and deportation defense. Administrative practice involves petitioning the U.S. government to allow a person to migrate to the U.S. on an immigrant or non-immigrant visa or as a refugee. This practice can be further broken down into business immigration, family based immigration and humanitarian based immigration. Deportation defense involves more classic litigation including interviewing and counseling clients, motions practice, legal brief writing, preparing lay and expert witnesses, oral arguments, and appellate practice. Given the high rates of immigration detention and the defensive posture, deportation defense is most like criminal defense in its practice.